Size dependence in magnetic memory, relaxation and interaction of La0.67Sr0.33MnO3

• Memory, relaxation and interaction of La0.67Sr0.33MnO3 particles, - bulk (60-150 µm) and nano (80nm) are reported.
• Magnetic relaxation studies suggest the existence of two relaxation times in both the cases.
• Dynamic light Scattering shows one size distribution for nano particles and another is for agglomerated particles.
• It has been noticed that both the samples show signature of magnetic memory and particles of two different sizes can relax separately.
• Nano particles are observed to favour demagnetized state where as bulk prefer magnetized state.

We report the study of memory effect, relaxation and interaction of La0.67Sr0.33MnO3 (LSMO) particles of two different sizes, bulk (~60–150 µm) and nano (~80 nm) synthesized by using polymeric precursor route. Magnetic relaxation measurement has been carried out and the analysis shows the existence of two relaxation times in both the cases. Our dynamic light scattering (DLS) studies indicate the presence of two different size distributions in LSMO nano particle sample. This is attributed to the fact that particles of two different sizes can relax separately. It has been observed that both the samples show signature of magnetic memory effect. Because, the effect of disordered surface layer is more in LSMO nano than LSMO bulk particles, LSMO nano particles are found to favor demagnetized state where as LSMO bulk prefer magnetized state.